In short
Grey corrugated cement sheet on a building put up before 2000 is very likely asbestos cement; a laboratory test of a small sample confirms it. Sound sheet can be left in place and managed. Removing it whole and wet is non-licensed work under the HSE's Control of Asbestos Regulations 2012, so the contractor does not need an asbestos licence, but sheets that will be broken up are notifiable non-licensed work, and the waste must leave with a registered carrier under a consignment note. MyJobQuote gives removal at around £60 a square metre and a garage at roughly £400 to £1,400, before the new roof.
This is a job for our Asbestos-cement roof replacement service.
How to tell
Age is the first clue: asbestos cement was the standard sheet on farm buildings, garages and lean-tos until the ban, and anything put up before 2000 is suspect. The sheet is grey, brittle, often mossy, with a slightly fibrous look at broken edges. A sample sent to a UKAS-accredited laboratory settles it for a few tens of pounds.
Leave it, seal it, or remove it
Leave it
Sound, undamaged sheet on a building nobody is altering is safest left alone and noted in the building's asbestos record. Do not pressure-wash it or drill it.
Encapsulate it
Coating and sealing weathered but sound sheet in place is cheaper than removal on a large shed and avoids the waste entirely.
Remove it
Cracked, crumbling or in the way of a conversion: it comes off.
What the rules say
The HSE classes removal of asbestos-cement sheet as non-licensed work when the sheets can be taken down whole and kept wet. Trained workers, no breaking, wrapped and labelled waste. If the sheets have to be broken up, it becomes notifiable non-licensed work: the HSE is notified, records are kept and the workers are under health surveillance. Either way the waste is hazardous, goes with a registered waste carrier under a consignment note, and only to a site licensed to take it. Most council tips will not.
What replacement costs
MyJobQuote's guide gives removal at around £60 a square metre, a garage at roughly £400 to £1,400 for the removal, and a survey at about £325. The new roof, in fibre cement or plastisol-coated steel, is on top. Farm sheds are priced by area and access.
Who does it
Farm roofers and specialist contractors across Powys and Ceredigion do this routinely. We pass your enquiry to one who covers your area; ask them to show the waste carrier registration and the consignment note before the job starts. Cambrian Roofing does not remove asbestos and holds no carrier registration.